The present invention relates to methods and apparatuses for laser projection. Moreover, the present invention is directed to machining methods for machining a workpiece using a working machine, and in particular relates to a machining method suitable for confirming a tool attached to a working machine.
Machining by an NC (Numerical Control) processing machine automatically proceeds in accordance with an NC program. Once machining starts, the progress of machining in accordance with an NC program is advantageous from a view point of an improvement in machining efficiency and the like, but if there is an error in the NC program, there is a problem that machining will progress without noticing the error. In order to accurately perform machining, an operator of a processing machine may input a correction numerical value in the middle of machining. In this case, for example if the operator inputs a wrong numerical value, there is a risk that wrong machining is performed as is. Furthermore, after all the machining operations are complete, there is a need to determine whether all the drawing-specified regions have been accurately machined. However, for example if there are many regions to be machined, there is a problem that a confirmation work takes time and/or a risk of overlooking an un-machined region.
In light of these problems, there are proposed a method and apparatus for determining, by projecting design information on a workpiece with a laser beam and confirming a projected laser locus by a person, whether machining as specified by design has been performed at a design specified position.
For example, Kaufman et al. describes, in U.S. Pat. No. 6,547,397, a laser drawing apparatus that scans a laser beam with two galvanomirrors. Kaufman et al. also describes, in U.S. Pat. No. 7,306,339, a method comprising the steps of: projecting a laser beam of a laser drawing apparatus onto a characteristic region of a workpiece; detecting a laser beam spread and reflected from the characteristic region of this workpiece; thereby recognizing a position (reference point on the workpiece) of the characteristic region of the workpiece; thereby recognizing a positional relationship between the workpiece and the laser drawing apparatus; and drawing design information or the like on the workpiece.
As a first example of a conventional machining method, for the purpose of removing a drawback of a lot of time required for setting a tool to an ATC (Automatic Tool Changer) and/or confirming the tool set in the ATC, and for simplifying this confirmation, there is known a working machine's tool management system capable of automatically managing tools without a person and of realizing automation of tool management (e.g., see Japan Patent No. 1931433). Specifically, the working machine's tool management system comprises: a working machine having tools of different shapes; a tool selection/drive control device for selecting a tool of this working machine; a tool recognition device for recognizing the shape of a tool; a central control unit that controls a tool recognition procedure, calculates tool recognition information of this tool recognition device, and controls the tool selection/drive control device; and a tool data generation device for preparing tool selection information, wherein the recognition information by the tool recognition device and tool data of the tool data generation device are compared and managed.
Secondly, there are known a tool observation method, a device therefor, and a cutting work system for accurately imaging a tool on machine with a tool observation technique of a cutting work device and for managing the tool based on this image (e.g., see JP−A-2001-269844). Specifically, there is provided the tool observation method comprising the steps of: imaging a state of a tool for cutting a workpiece, with an imaging unit; and observing the tool based on this image information, wherein a plurality of images of the workpiece are captured while rotating or moving the tool at least before or after machining the workpiece with the tool, and wherein a focused image among the plurality of images is selectively used for observation.
Thirdly, a tool management device in a working machine is known, which eliminates a work for confirming tool storage positions in a tool magazine where a plurality of tools are to be stored, the work being performed by an operator, and which quickly and reliably performs the work for storing the tools into the tool magazine (e.g., see JP−A-2005-324262). Specifically, a normal tool is imaged and stored into a first tool image data storage unit. Next, tool management information including a tool number relating to first tool image data is stored into a first tool management information storage unit. Then, a plurality of tools to be used are randomly mounted on the tool magazine without taking a machining sequence into consideration, and the tools are imaged and stored into a second tool image data storage unit. Further, second tool image data is collated with the first tool image data. If the both data coincide with each other, the tool management information including the tool number of the first tool image data is set as tool management information of the second tool image data. Furthermore, by analyzing a machining program, the storage positions of the tools in the tool magazine are shuffled so as to minimize a total machining time.
Fourthly, there is known an apparatus capable of finding automatically and in advance a mounting mistake of a tool T onto a magazine 1 and furthermore realizing automatic measurement and automatic correction of a high precision tool T (e.g., see JP−A-6-134638). Specifically, a captured image of the tool T1 is transferred as image information to an image processing unit 8a of a personal computer 8 from an imaging unit 5. This image information is processed in an image processing unit 8a, and then sent to a tool feature quantity calculation unit 8b. The tool feature quantity calculation unit 8b extracts and calculates a feature quantity of the tool T1 from this image data. Then, a collation and recognition unit 8c collates the feature quantity data of the tool T1 extracted and calculated by the tool feature quantity calculation unit 8b with master data P1 regarding the tool T1 to recognize whether or not an imaged tool T1 coincides with a tool T1 specified by an NC apparatus 3.